Toothbrushes are widely accepted by consumers as one of the best instruments for preventing tooth decay. Early toothbrushes generally included a handle made of a single component with a plurality of filaments attached thereto. However, with the progression of technology, particularly in the areas of plastics processing, toothbrushes have become more complex. For example, some toothbrushes currently available have a handle which includes multiple plastic materials.
The utilization of multiple materials in a toothbrush often leads to manufacturing complexity. For example, in a first injection molding step, a body of the toothbrush may be produced. Additional injection molding steps may be required for each additional material placed on the body. While the additional materials can result in an aesthetically pleasing brush, the additional materials can also lead to additional manufacturing steps which results in a higher production cost.
Complex formations or shapes on the toothbrush can similarly lead to additional manufacturing steps and higher costs. As an example, some edges may be formed at an angle with respect to a longitudinal axis of the toothbrush which can lead to manufacturing complexity. In general, when an edge is angled, the molding operation for the angled edge can be more complicated than an edge which is generally perpendicular to the longitudinal axis. This is particularly applicable where the separation of mold halves is in the vertical direction (perpendicular to the longitudinal axis). The angled edge can cause an undercut. An undercut occurs, for example, when a mold cavity comprises an opening which has a smaller dimension than a portion of the toothbrush which the smaller dimension has to cross in order to achieve mold removal. Where an undercut is present a more complex molding operation may be utilized. For example, mold components which move laterally (perpendicular to the vertical direction) can be utilized. However, the implementation of such mold components complicates the molding operation and also increases the cost of production of the toothbrushes.
Accordingly, there is a need for toothbrush which includes complex features and/or shapes which can be produced via an injection molding operation.